Metal cleaning composition



Patented Oct. 10, 1950 METAL CLEANING coMrosrrIoN' Arthur 0. Pabst, Douglaston, and Eleanor S.

Salmon, New York, N. Y., assignors to Socony- Vacuum Oil Company, Incorporated,'a corpo-- ration of New York No Drawing. Application October 8, 1947,

Serial No. 778,732

This invention relates to improved metal cleanins-compositions and their use. It is particularly 1 directed to metal cleaning compositions capable of removing rust, scale, grease and other deposits from metal surfaces.

One of the main uses for such a composition is in the cleaning of water cooling systems such as are used in internal combustion engines. Such systems gradually become fouled during use and unless periodically shut down and cleaned, the water jackets and radiators become coated with deposits which interfere with the heat transfer and in severe cases may be plugged to a point of p ete stoppage of coolant circulation. The composition of the deposits may vary depending upon the construction materials of the coolant system. Such metals as solder, copper, zinc, lead and iron may be used in one form or another and. of these, iron in its various modifications is the chief component. Grease may enter the cooling system from grease packed water pumps and oil or oxidized hydrocarbons may enter from blowby from the combustion chamber or from other sources. Certain other foreign deposits may be introduced with the coolant especially when it is water. A common components of the fouling deposits is iron oxide cemented fast to the metal surface by adsorbed or oxidized oil. Such a scale especially when covered with a coating of grease or oil is very diflicult to remove.

Similar conditions prevail and similar contaminants consisting of oxidized metal and oily substances are usually present on the surfaces of machine parts which are to be cleaned in shops. The cleaning operations usually comprise degreasing, pickling and de-rusting.

Cleaning compositions used at present for automotive cooling systems may be generally classified under one of three types. One type consists of an aqueous solution of an alkaline salt such as washing soda, trisodium phosphate, etc. This type acts very slowly on rust and scale so that only small amounts of the deposits are removed in the time normally given the radiator flushing. Moreover, it removes very little of the oil or grease deposits. A second type of cleafig consists of an alkaline emulsion of hydrocarb and other organic s01- vents. This type will remove the'oil and grease deposits fairly satisfactorily but will remove only very small amounts of rust and scale deposit; consequently, the system is not entirely cleaned. The third type of cleaner consists of aqueous solutions of acids or acid salts, such as hydrochloric and oxalic acids and sodium bisulfate. This type is very efiective in removing rust and scale but will 8 Claims. (c1. asa -143) remove very little grease or 011 deposit. More over, the'acid type cleaner is highly corrosive and requires a follow-up flush with an alkali to stop the action of the acid. This. is not always satisfactory in entirely avoiding corrosion as it is often diflicult to obtain complete acid neutralization.

A major object of this invention is the provision of a new and novel cleaning composition which is capable of removing rust, scale and oily deposits.

A further object of this invention is the pro- A vision of a cleaning composition which will rapidly remove rust and scale deposits from metal surfaces without causing rapid after corrosion of the metal surface.

Another object is the provision of a rapid method for cleaning metal surfaces and cooling systems which will not cause considerable surface corrosion. These and other objects will become apparent from the more detailed description of the invention following hereinafter.

We have now discovered that certain oil-in-acid solution type emulsions will rapidly remove rust and scale from metal surfaces and at the same time dissolve and emulsify any oil and grease present. Tests also indicate that the product has remarkable properties in inhibiting corrosion so that it is unnecessary to follow up with an alkaline wash. In other words, the product offers the main advantages of each of the types of common radiator flushes without their disadvantages and failings. Moreover, the product of this invention may be packaged in concentrated form and will remain stable and substantially unchanged after long periods of storage. Thus the product ,in a very small container may be stored on a shelf for a period of months and then when needed it may be readily diluted in water to provide a cleaning emulsion of the desired strength for cleaning metal surfaces such as in automobile radiators.

The cleaning composition of this invention consists of a dispersed phase of an emulsiflable organic water-insoluble material and a continuous phase of a strong aqueous solution of hydrochloric acid, and a specific emulsifying agent capable of producing emulsions sufficiently stable both for long shelf storage prior to use and for subsequent dilution if desired at the time of use while still forming a stable emulsion. The continuous phase should consist of an aqueous solution of hydrochloric acid in which the concentration of pure HCl is within the range 10-30 .percent by 'weight and preferably within the range 15-25 percent by weight. It is by virtue of these high acid concentrations that the cleaning com osition can be prepared long periods before it is to be actually used and packaged in relatively small bulk as compared with the bulk of the diluted cleaning emulsion which is actually finally employed for cleaning the automobile radiator. The dispersed phase may consist either of hydrocarbon solvents or of halogenated hydrocarbon solvents or mixtures thereof; exemplary are kerosene and orthodichlorbenzene. Halogenated hydrocarbons either alone or in admixture with straight hydrocarbons are particularly desirable as they tend to form stable emulsions more readily. Such hydrocarbons and halogenated hydrocarbons should boil above about 160 F. in order to prevent loss thereof by evaporation during use. Preferably the halogenated hydrocarbons and particularly the hydrocarbons should boil above about 250 F.

The emulsifier to be used is one capable of 20 4 mol of beta-hydroxyethyl ethylene diamine with 0.5 mol of commercial oleic acid and then heating under reflux for about 5 hours until a final temperature of about 507 F. is reached. During this period about 2 mols of water per mol of oleic acid are distilled oil. Excess hydroxyethyl ethylene diamine is then removed and the product, l-hydroxyethyl 2-heptadecenyl glyoxalidine is purified by vacuum distillation. We have found it preferable to employ mixtures of l-hydroxyethyl 2-heptadecenyl glyoxalidine and an iso-octyl phenyl polyglycol ether of about 650 molecular weight in our cleaning composition. Mixtures of these emulsifiers have been found to result in even more stable oil in acid emulsions than compositions employing only one of the emulsifiers.

The following examples will illustrate the type of emulsions made and used according to this invention.

Emulsion No I II V V VI VII VIII Ix X Comtituente Weight Weight Weight Weight Weight Weight Weight Weight Weight Weight Per cent Per cent Per cent Per cent Per cent Per cent Per cent Per cent Per cent Per cent Orthodichlorbenzene 20. 20. 0 2). 0 39. l9. 5 19. 0 Carbon Tetrachloride. 21.0 Kerosene 20. 0 19. 5 19. 5 19. 0 10. 5 30. 0 30. 0 15. 0 Naphtha (250-450" F. boiling range) m0 Concentrated H01 (38%) 58. 5 27.0 27. 0 27.0 50. 0 27. 0 15. 9 15. 9 15. 0 27. 0 l-hydroxyethy] 2-heptadecenyl glyoxslidina 1. 5 1. 5 5. 0 1. 5 1. 5 5. 0 Para-iso-octyl polyglycol phenyl ether (10 mols glycol per mol of iso-octyl phenol M. W. @650) 1.5 1.0 1.0 5.0 1.5 3.0 Water. 320 32. 0 28. 5 32. 0 49. 1 49. 1 52. 6 30. 0

giving either a completely stable emulsion or a readily redispersable product when the emulsion is stored over long periods of time, for example as shelf goods. We have found that a stable oil in strong hydrochloric acid solution emulsion may be provided when our cleaning composition contains as an emulsifier a compound which may be expressed by the formula where R is a di-isobutyl phenyl radical and n is a number between about 6 and and preferably equal to about 10. This emulsifier may be referred to generically as iso-octyl phenyl polyglycol ether or polyethylene glycol mono isooctyl phenyl ether. This emulsifier may be prepared as described in the following example:

206 parts of para-iso-octyl phenol (obtainable by condensing phenol with di-iso-butylene by known methods) .are melted and 2 parts of a caustic soda solution of percent strength are added thereto. Ethylene oxide' is introduced, while stirring at a temperature of 248 to 267 C. until 10 mols of ethylene oxide per one mol of para-iso-octyl phenol have been absorbed. The resulting product is a para-iso-octyl phenyl polyglycol ether having a polyglycol radical consisting of 10 molecular proportions of glycol and a total molecular weight of about 646.

Using the same method described above but limiting the amount of ethylene oxide absorbed to about six mols per mol of iso-octyl phenol an emulsifier having a molecular weight of about 470 may be obtained. While it is preferred that the iso-octyl phenyl polyglycol ether employed have a molecular weight of about 650, still in less preferred forms of this invention it may vary in molecular weight within the range about 470 to 875.

Another emulsifier which may be employed is 1 hydroxyethyl 2 heptadecenyl glyoxalidine.' This compound may be prepared by mixing one These emulsions are prepared by dissolving the emulsifier in one of the phases, generally the one in which the emulsifier is most soluble, and then adding the other liquid phase while stirring the liquid with a high speed mixer. The hydrocarbon emulsion in aqueous acid thus formed maybe further diluted with water, if desired. Either the cationic emulsifier l-hydroxyethyl 2-heptadecenyl glyoxalidine or the non-ionic emulsifier, polyethylene-glycol mono iso-octyl phenyl ether are soluble in the oil phase and may be dissolved therein and the acid then added. Moreover, the former emulsifier is also soluble in aqueous acid solution, so that it may first be dissolved therein and the oil phase added with mixing. The desirable amount of emulsifier to be used may vary between 0.1% to 5.0% by weight of the emulsion. In use the prepared emulsion may be added to the cooling system or to a, circulating bath in concentrations controlled to provide the desired cleaning rate. Thus, for example, such prepared emulsions as shown in the above table may be added to water in a cooling system in concentrations of 5% emulsion and upwards. In any event the pH value of the liquid circulated in the cleaning system should be below 4.0, and the acid concentration in the continuous phase should be of the order of about 1.0% by weight HCl, and upwards.

After the emulsion is added to the coolin system or cleaning bath, it is heated either by a heater or by starting the engine involved and the heated emulsion is circulated. After about 20 to 30 minutes of circulation, the system is drained and flushed by filling with water and running the engine until warm. The water is then drained and the system refilled with cooling water. After such a treatment, the metal surfaces of the cooling system are thoroughly clean" bath of the emulsion for a set period, then resitions. The stable hydrocarbon-in-acidic-so1u moved and rinsed in clean water. No neutraliztion emulsion permits a uniformity of hydrocaring chemicals need be added to the rinsing bon distribution throughout the cleaning solution water to prevent corrosion of the metal cleaned. so that it may perform its funtion uniformly In addition to the practical tests on automobile over the entire surface of the metal to be cleaned. cooling systems, as described hereinabove, labora- To further prove that the emulsion type cleantory tests were also made to establish the relative ing compositions of this invention are less corcleaning efliciencies of these novel emulsions and rosive on the metal surfaces or cooling systems of certain cleaning compositions used commerbeing cleaned, even while being used, a number cially heretofore. Rustedsteel plates were imof uniform strips of the metals commonly enmersed in the boiling solutions in concentrations countered in cooling systems were immersed in.

recommended by the respective manufacturers, several diiferent cleaning liquids for a period of and the time required for completion of cleaning 24 hours and the corrosion loss was then measwas taken as a measure of efliciency. The after ured.

corrosion of the metal was particularly noted.

' Corrosion Ooncentrat i b i fi gf on of Time in Active Acid ours Aiter-eor- Cleaning Compound meaning compound tfls ttfl were... g in still; 8 Cleanin cl n Bath Iron Bath g g der GmJliler G Milli- Milli Oxalic Acid type 20 noticeable. om A id t m-l ztego grams grams Sodium bisulfate type 20 :10 Do. Y 146 gg gfggor g ac g ypg 23 7 smugi u l i gi l l g fi fi' II lg %31 emulsion n to 9 g Sodium bisulfate type 20 300 21.1 of water) l0 7 none. I

It should be understood that the specific ex- It will be apparent from the above that the amples of the emulsion type cleaning composiemulsions of this invention have substantially the tions and of their application as given herein- S me u removing P w r a o g acid type above are intended merely as exemplary and are commercial cleaning compositions while at the not to be construed as limiting the scope of this same time protecting the metal surface cleaned invention thereto. These compositions present from after corrosion. Moreover, the emulsions a very considerable and useful stability over re have a far greater grease and oil removing power lated compositions known to the prior art as may than the acid or acid salt type cleaning compobe seen from the following data.

Acid emulsions-Metal cleaning compounds 1 2 3 4 5 6 7 8 9 l0 l1 l2 i3 14 Concentrated HCl (38%) 59.0 59.0 59.0 59.0 59. 0 59. O 59. 0 15. 9 15. 9 15.9 27.0 15. 9 l5. 9 Hydrocarbon solvents of kerosene boiling range 19. 0 l9. 5 17. 5 19- 5 19. 5 19. 5 l9. 5 30. 0 30. 0 30. 0 19. O 30. 0 30. 0 15 O Orthodichlorbenzene l9. 5 20. 0 18. 5 20. 0 20. 0 20. 0 20. 0 19. 5 15 0 l-hydroxyethyl, 2-heptadecenyl.

g yoxalidine.-. 1. 5 1.5 5.0 Pol eth lene'glycol mono iso-oetyl p eny ether 15 1.0 1.0 5. 0 1. 5 Oleic A 5.0 Sodium Lauryl Sulfate l. 5 5.0

Gum Trarammih 1. 5

Po yethy ene Glycol Monoleate 600- 1. 5

P0 yEL'uy one Glycol Dioleate 600" 1. 5

Po yethy ene 01 col Oleate 400L.. 1.5 P0 yetlly cup G ycol 1000 1110110- nle- 5. 0 .5. 0 5. 0 Polyethylene Glycol 1000 di-oleate. 10.0 10.0 Polyethylene Glycol 4000 di-oleate. 10.0 water 34.1 34.1 34.1 32. 0 49.1 49.1 52. 6

1 Emulsion stable for 1 day. Separates into 2 emulsion layers in 3 days. Redispersed by simple shaking after 6 months. Forms stable emulsion when diluted, can be boiled.

i Unstable. 'lotal Separation and no redispersion after 5-10 minutes.

8 Unstable. Separation begins within 5-10 minutes. Total separation and no redispersion after 12 hours.

4 No emulsion. Water phase too thick. Cannot be dispersed.

5 Stable for 1 day. Separates into 2 clear phases in 3 days and cannot be redispersed by vigorous shaking. Cannot be diluted. Forms no emulsion in water.

6 Stable for 1 day. Separates into 2 clear phases in 3 days and cannot be redispersed by vigorous shaking. Cannot be diluted. Forms no emulsion in water.

1S Stabilg fortl day. Separates into 2 clear phases in 3 days and cannot be redispersed by vigorous shaking. Cannot be diluted. Forms no emu run we er.

8 Emulsion separates into 2 opaque layers overnight. Ma be redispersed by mild agitation. After 4 days separates into 2 layers which cannot be recombined by vigorousagltation. No longer comp etely disperses in water.

P Separates into 2 layers over-night which recombine by mild agitation. After 4 days separates into clear oil layer and opaque layer cannot be redispersed by shaking. No longer completely disperses in water.

Separates permanently on standing over-night into one clear oil layer and an opaque layer. Cannot be redispersed by shaking. No longer disperses completely 1!] water.

H Separates into 2 emulsion layers in 3 days which may be redispersed by simple shaking. After 6 months separates into 2 emulsion layers which may be redispersed by simple shaking. After 6 months still forms stable emulsion when diluted. Can be boiled.

11 After days storage separates into 2 emulsion layers and a very slight water layer which may be redisperesd by simple shaking. After 65 days still forms stable emulsion when dlluted with water.

1! After days storage separates into 2 emulsion layers and a very slight water layer which may be redispersed by simple shaking. After 75 dayggtilgorims stable emulsiontwlilellti i'llutedlwithI water. d slight 1 h h 14 er 5 ays s orage separa es 0 emu sion ayers an a very water ayer w ic me be redis ersed b sim le shakin Al e 75 days still forms stable emulsion when diluted with water. y p y p g t M. W. 650-i. e., containing about l0 molecular portions of (C11: CHaO).

In the above table compositions numbered 1, 11, 12, 13 and 14 are compositions prepared according to the instant invention, compositions 1 and 11 representing the preferred form of the invention. Compositions 2and 3 employ an emulsifler which has been used in the prior art in preparing oxalic acid emulsions. Compositions 4-10 are typical of the emulsions shown in United States Patent 2,269,529 issued January 13, 1942, to Goldsmith. It will be seen that the compositions prepared according to the method of this invention are stable in that after long periodsoi standing no clear oil layer separates and the emulsion layers which do separate may be redispersed by simple shaking to provide an emulsion having substantially the same appearance and properties as the composition when originally made. Moreover, the cleaning compositions of this invention after long periods of standing (65 days-8 months and upwards) can be diluted with water to form a completely dispersed stable emulsion. This dilute emulsion can be boiled without destruction of the emulsion. It will be noted that in the case of compositions 2-10, upon standing from one to six days, a clear oil layer separates out indicating complete break down of the emulsion. The separated layers in the latter compositions cannot be redispersed even on vigorous shaking and cannot be dispersed completely in water upon dilution. It will be apparent that in the case of compositions 2-10, these compositions cannot be employed for cleaning metals or.

automobile radiators after having been stored for any appreciable time without danger of severe corrosion of the metal surfaces due to the acid. The compositions of the instant invention on the other hand being stable emulsions do not involve this critical difficulty.

This case is a continuation in part of ourap- I plication Serial Number 616,479, filed September 14, 1945 (now abandoned), which is in-turn a continuation in part of our application Serial Number 562,902, filed November 10, 1944 110wabandoned. p

Weclaim:

1. A metal cleaning composition in the form of an oil-in-water' emulsion which comprises, a dispersed phase of a substantially water-insoluble organic solvent selected from the group consisting of kerosene, naphtha boiling within the range about 250 F. to 450 F. and liquid chlorinated hydrocarbons boiling above about 160 F. and mixtures of the same, a continuous phase of an aqueous solution of hydrochloric acid in which the percentage by weight HCl is within the range 15 to 25, and about 0.1 percent to about 5.0 percent by weight of the emulsion of iso-octyl phenyl poly lycol ether having a molecular weight of about 650 as an emulsifier.

2. A metal cleaning composition in the form of R (CH2.CH2O) "H wherein R stands for a di-iso-butyl phenyl radical and n stands for a whole number from 6-15.

3. A metal cleaning composition in the form of an oil-in-water type emulsion which comprises, a dispersed phase of an emulsiflable organic water-insoluble solvent selected from the group consisting of kerosene, naphtha boiling within the range about 250 F.-450 F'., liquid chlorinated hydrocarbons boiling above about 160 F. and mixtures of the same, a continuous phase of an aqueous solution of hydrochloric acid in which the concentration of HCl is within the range about 10 to' 30 percent by weight and about 0.1 to 5.0 percent by weightof the' emulsion of an emulsifier consisting of a mixture of l-hydroxyethyl 2-h epta deceny1 glyoxalidine and iso-octyl phenyl polyglycol ether having a molecular weight within the range about 470-875.

4. A metal cleaning composition in the form of an oil-in-water type emulsion which comprises,

a dispersed phase of a solvent selected from the nowmcmm 10H wherein R. stands for a di-isobutyl phenyl radical.

5. A metal cleaning composition in the form of an oil-in-water type emulsion which-comprises, a dispersed phase consisting of a mixture of kerosene and orthodichlorbenzene, a continuous phase of an aqueous solution of hydrochloric acid in which the concentration of HCl is within the range about 10 to 30 percent by weight and about 0.1 to 5.0 percent-by weight of the emulsion of an emulsifier consisting of a mixture of l-hydroxyethyl Z-heptadecenyl glyoxalidine and the prodnot of the general formula wherein R stands for a di-isobutyl phenyl radical.

A metal cleaning composition in the form of an'pil-in-water type emulsion which comprises, a dispersed phase of a mixture of a hydrocarbon solvent fraction boiling above about 250 F. and

- not above about 450 F. and orthodichlorbenzene,

a continuous phase of an aqueous solution of hydrochloric acid in which the concentration of HCl is within the range about 10-30 percent by weight, and about 0.1-5.0 percent by weight of the emulsion of an emulsifier which is a compound having the formula wherein R stands for a di-isobutyl phenyl radical and 1: stands for a whole number within the range 6-15.

7. A metal cleaning composition in the form of an oil-in-water type emulsion which comprises, a dispersed phase of a mixture of a naphtha boiling within the range about 250 F.-450 F. and carbon tetrachloride, a continuous phase of an aqueous solution of hydrochloric acid in which the concentration of HCl is within the range about 10-30 percent, and about 0.1 to 5.0 percent by weight of the emulsion of an emulsifier which is a compound having the formula nowmcmonn wherein R stands for a di-isobutyl phenyl radical and 1: stands for a whole number within the range 8. A metal cleaning composition in the form oi an oil-in-water type emulsion which comprises a dispersed phase consisting of kerosene, a contin- 10 Rnmmcns crmn The following references are of record in the me of this patent:

UNITED STATES PATENTS Number Name Date Amthor Apr. 7, 1936 Ryznar Nov. 4, 1941 Goldsmith Jan. 13, 1942 Katzman Nov. 24, 1942 Douty Mar. 19, 1946 Campbell Apr. 30, 1946 Szatyn Apr. 30, 1946 

1. A METAL CLEANING COMPOSITION IN THE FORM OF AN OIL-IN-WATER EMULSION WHICH COMPRISES, A DISPERSED PHASE A SUBSTANTIALLY WATER-INSOLUBLE ORGANIC SOLVENT SELECTED FROM THE GROUP CONSISTING OF KEROSENE, NAPHTHA BOILING WITHIN THE RANGE ABOUT 250*F. TO 450*F. AND LIQUID CHLORINATED HYDROCARBONS BOILING ABOVE ABOUT 160*F. AND MIXTURES OF THE SAME, A CONTINUOUS PHASE OF AN AQUEOUS SOLUTION OF HYDROCHLORIC ACID IN WHICH THE PERCENTAGE BY WEIGHT HCL IS WITHIN THE RANGE 15 TO 25, AND ABOUT 0.1 PERCENT TO ABOUT 5.0 PERCENT BY WEIGHT OF THE EMULSION OF ISO-OCTYL PHENYL POLYGLYCOL ETHER HAVING A MOLECULAR WEIGHT OF ABOUT 650 AS AN EMULSIFIER. 